Spool valve

ABSTRACT

A fluid-pressure operated spool valve for controlling movements of a fluid-pressure responsive device is provided with an armature carried by each end of the valve spool externally of any fluid chamber for reciprocation with the valve spool. A magnet is carried in each end of the valve body in a position to attract and releasably hold the adjacent armature without contact between the magnet and the armature.

11, States Patent 1 1 Norton et a1.

1451 Nov. 12, 1974 1 SPOOL VALVE [76] Inventors: Orien K. Norton, 2011 Elizaville Rd., Lebanon, 1nd. 46052; David E. Grimes, 26 Del Mar Dr., Crawfordsville, 1nd. 47933; Ralph A. Sayler, PO. Box 98, New Market, 1nd. 47965 [22] Filed: Oct. 30, 1972 [21] Appl. No.: 302,113

[ 52] US. Cl 251/65, 251/319, 91/275 [51] Int. Cl. F16k 31/08 [58] Field of Search 251/65, 75,319, 320, 318

[56] I References Cited 1 UNITED STATES PATENTS 2,708,944 5/1955 Modine 251/65 3.326.236 6/1967 Beckett et al 251/65 Primary E.raminer--Edgar W. Geoghegan Assistant E.\'uminerWilliam F. Woods Attorney. Agent, or Firni-Trask, Jenkins & Hanlcy [57] ABSTRACT A fluid-pressure operated spool valve for controlling movements of a fluid-pressure responsive device is provided with an armature carried by each end oi the valve spool externally of any fluid chamber for reciprocation with the valve spool. A magnet is carried in each end of the valve body in a position to attract and releasably hold the adjacent armature without contact between the magnet and the armature;

6 Claims, 4 Drawing Figures MENTED NOV 1 2 I974 SNEEI IN 2 PATENTEUNUV 12 I974 SPOOL VALVE" BACKGROUND OF THE INVENTION This invention relates to a valve, and more particularly to an improvement in a fluid-pressure operated spool valve for use in controlling movements of a fluid-' '14 operatively connect the valve to ajfluid- Work ports of the valve may be connected with a work cylinder piston. Examples of the construction and operation of valves of this type maybe found in U.'S.,Pat.

, Nos. 2,586,906, 2,869,583, 2,908,292 and 3,203,439.,

. Such spool valves have proved useful'as controls for various work producing mechanisms. For example, a spool valve controlling a pneumatic cylinder piston may beused in conjunction with a blade assembly for cutting crops. However, such systems may malfunction,

' producing mechanism such as a hydraulic or pneumatic especially at relatively fast speeds. And it is possible for the cylinder tostall and the spool valve to continue to operate, but at a different speed. The lack of positive valve actuation and the failure to deliver fullpressure to the cutting assembly or other device until the end of the stroke are also common shortcomings.

SUMMARYOF THE. INVENTION This invention p'rovides positive spool valve actuation and the delivery of full pressure throughout the stroke. A positive force is required in order to actuate the valves so thatinadvertent or premature actuation may be avoided. I

The ends of the valve spool are provided with magnetic armatures which are external of any fluid chamber. An annular maagnet is secured in'each end wall of the valve body adjacent to and'encircling the bore and valve spool, and recessed from the surface of the valve body. The annular magnet is thus in a position to attract and releasably hold the adjacent armature, but without any physical contact between them.

BRIEF DESCRIPTION OF THE DRAWINGS The invention as illustrated in the drawings in'which:

FIG. 1 illustrates a spool valve connected with cutting assemblies;

FIG. 2 is a cross-sectional view of the spool valve;

FIG. 3 is a generally schematic view illustrating the spool valve and its connections with a fluid source and fluid-pressure responsive cylinder; and

FIG. 4 is a viewlike that of FIG. 3 but with the spool valve shifted in the opposite direction.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT A fluid-pressure operated valve operated valve 10 is supported in a fixed position adjacent the underside'of a supporting member 12. The member 12 maybe attached to the'frame of an appropriate vehicle, such as a l-li-Boy, for usein cutting crops. Fluid hoses 13 and responsive device such as cylinder 15. The cylinder 15 has a movable rod 16 which'is connected with a movable arm 18. The arm 18 is capable of being moved alternately to the right and to the left as illustrated by the arrows in FIG. 1. a Adjacent the ends of the arm 18 are cutting assemblies 22 and24. Each cutting assembly comprises a pair of stationary blades 26 with a cooperating movable :blade 28 therebetween. The blades 28 are connected to the arm l8for movement therewith, and the blades 26 are fixedly supported from the underside of the member 12. Arm l8 isslidably supported by brackets 30 which are attached to the undersides of the blades 26.

A fluid hose 32 connects aninlet port 34 of valve 10 to a fluid-pressure source such as the hydraulic fluid tank 35 and pump 37, as illustrated in FIGS. 3 and 4. Work ports 36 and 38 of valve 10 are connected by hoses 13 and 14 to opposite ends'of the cylinder 15 The valve 10 also has an exhaust port 39.

A bracket-40 is connected with the arm 18 on each side of the valve 10. Each bracket 40 has aspring 42 mounted thereon to cushion contact between the brackets and the external portions of the valve 10.

As best seenin FIG. 2, the valve 10 has a body 50 with end walls52' and 54. A bore 56 extends longitudinally through the body .50 from one end wall to the other with bore openings 58 and 60 in the end walls. An elongated valve spool 62 is slildably carried inthe bore 56' so as to be reciprocable of the bore between operative positions. In other words, the valve spool 62 is capable of being moved alternately to the right and to the left as illustrated by the arrows inFIGS.;l and2. Pressure sealing O-rings 64 are provided, adjacent each of the bore openings.

The valve spool 62 has end portions 66.and 68 extendijng from the bore 60 externally of the body 50 beyond the end walls 52 and 54. A collar or armature 70 of magnetic material is carried by the end 66 of valve spool 62, and a similar collor or armature 72 is carried between the magnet 74 and the armature 70. The magnet 74 may be secured in place, recessed in the surface of end wall 52, by applying a light adhesive on its bottom and by peaning over portions of, the end wall 52. In like manner, an annular magnet 76 is secured in end wall 54 recessed from its surface. The magnet 76 and the armature 72 are structurallly and operationally the same as the magnet 74 and armature 70.

As best illustrated in FIGS. 3 and 4, the valve spool 62 may be shifted to the right or to the left and will be releasably held in either position by the attraction between the armature and the magnet 74, or the armature 72 andthe magnet 76.

Hydraulilc fluid from tank 35 is pumped through the fluid hose 32 and into inlet port 34 by the pump 37.

Shifting the valve spool 62 to the right (FIG; 3) causes fluid under pressure to pass through the port 38 and the hose 14 to the rightend of the cylinder 15, moving the rod 16 to the left. The hose 13 then acts as an exhaust line at the other or left end of the cylinder 15, carrying the fluid into the port 36. When the valve spool 62 is reversed, that is, shifted to the left (FIG. 4), the fluid under pressure passes through the port 36 and hose 13 to the left end of the cylinder 15. This causes the rod 16 to move to the right, as indicated. In this situation, the hose l4 acts as an exhaust line carrying the fluid into the port 38. In both situations, the fluid passes through exhaust port 39 for return to the fluid tank 35. If penumatic rather than hydraualic pressure is used, the hose 32 would be connected to an air supply, and

4 externally of any fluid chamber, and a magnet secured in each of said end walls externally of any fluid chamber and in a position tov attract the adjacent armature.

2. The invention set forthin claim 1 wherein sid magnets are carried in said end walls recessed from the surfaces of said end walls.

3. The invention set forth in'claim I wherein said magnets are located adjacent to the bore openings in the exhaust port 39 would exhaust into the atmmosphere, desirablywith a muffler installed in the exhaust 7 port.

Since the rod 16 is connected with movable arm 18, the arm 18 moves to the right or left as the rod moves to the right or left. When the rod 16 and arm 18 move to the left (as in FIG. 3), the spool valve 62 is shifted to the right. The arm 18 moves to the left until the spring 42 of'the bracket 40 contacts the armature 72.

(See FIG. 1.) This contact is of sufficient force to' overcome the holding forcebetween the armature 70 and the magnet 74, and the spool valve will then be shiftied to the left thus causing the rod 16 and the arm 18 to v move to the right (as in FIG. 4). The direction of movefrom one end wall to the other with bore openings in said end walls, and an elongated valve spool carried within and longitudinally reciprocable in said bore between operative positions, the improvement comprising an armature carried by each end of said valve spool said end walls.

4. The invention set forth in claim 3 wherein said annular magnets encircle the bore openings in said end walls.

5. In a valve wherein the valve has a body with opposite end walks and a bore extending through said body from one end wall to the other with a bore opening in each of said end walls, and an elongated valve spool carried within and longitudinally reciprocable in said bore between operative positions, the improvement comprising an armature carried by each end of said valve spool externally of said valve body for reciprocation with said valve spool, and an annular magnet carried in each of said end walls externally of any fluid chamber and recessed from the surface of said end wall and encircling the bore opening in said end wall.

6. In automatic valve for controlling movements of a fluid-pressure responsive device wherein the valve has a body with opposite end walls and a bore extending through said body from one end wall to the other with a bore opening in each of said end walls, and an elongated valve spool carried within and longitudinally re- .ciprocable in said bore between operative positions,

I the improvement comprising a magnetic armature carsurface of said end wall and encircling the bore opening in said end wall in a position to attract and releasably hold the adjacent armature without physical contact between said armature and said magnet.

l l l l 

1. In a valve wherein the valve has a body with opposite end walls and a bore extending through said body from one end wall to the other with bore openings in said end walls, and an elongated valve spool carried within and longitudinally reciprocable in said bore between operative positions, the improvement comprising an armature carried by each end of said valve spool externally of any fluid chamber, and a magnet secured in each of said end walls externally of any fluid chamber and in a position to attract the adjacent armature.
 2. The invention set forth in claim 1 wherein sid magnets are carried in said end walls recessed from the surfaces of said end walls.
 3. The invention set forth in claim 1 wherein said magnets are located adjacent to the bore openings in said end walls.
 4. The invention set forth in claim 3 wherein said annular magnets encircle the bore openings in said end walls.
 5. In a valve wherein the valve has a body with opposite end walks and a bore extending through said body from one end wall to the other with a bore opening in each of said end walls, and an elongated valve spool carried within and longitudinally reciprocable in said bore between operative positions, the improvement comprising an armature carried by each end of said valve spool externally of said valve body for reciprocation with said valve spool, and an annular magnet carried in each of said end walls externally of any fluid chamber and recessed from the surface of said end wall and encircling the bore opening in said end wall.
 6. In automatic valve for controlling movements of a fluid-pressure responsive device wherein the valve has a body with opposite end walls and a bore extending through said body from one end wall to the other with a bore opening in each of said end walls, and an elongated valve spool carried within and longitudinally reciprocable in said bore between operative positions, the improvement comprising a magnetic armature carried by each end of said valve spool externally of any fluid chamber for reciprocation with said valve spool, and an annular magnet carried in each of said end walls externally of any fluid chamber and recessed from the surface of said end wall and encircling the bore opening in said end wall in a position to attract and releasably hold the adjacent armature without physical contact between said armature and said magnet. 